In general, when a data carrier with a web server is used in such or a similar way, the total data traffic during an existing communication link between a terminal of a user and an external server takes place via the data carrier. In the case of large amounts of data to be transferred, for example for graphical elements, this occasionally leads to problems with regard to the memory capacity of the portable data carrier and the attainable data transfer rate of data transmission from the web server via the portable data carrier to the terminal.
WO 2005/091107 A1 discloses a browser plug-in for a web browser which makes it possible to check URLs (Uniform Resource Locators) of web resources, such as web pages or web services, for security risks potentially emanating from the resources. For this purpose, the plug-in compares a URL transmitted by the browser, before the URL is resolved and the corresponding web resource loaded, with URLs in a list of putatively security-critical URLs (a so-called “blacklist”) and outputs a security warning if the transmitted URL is to be found in the list and thus to be considered a potential security risk. The list can be internally stored or be queried interactively by the plug-in via a database.